This invention pertains to a locking system for a blending or blender device and particularly to a blender that involves a jar that is fitted into a holder to form a two-part blender assembly.
In the past twenty years or so, blenders have become extremely popular for use in the kitchen in order to thoroughly mix and blend ingredients in a jar. One of the earliest of these devices features a one-piece or unitary jar having the blades or impellers fixedly located in the bottom of the jar, the blades being connected through a sealing assembly to a suitable drive means in the base of the unit or machine.
Although the above-described blender devices have been efficient, it has become the practice, because of the cost factor and for greater ease in cleaning, to manufacture the blender in two separable parts, that is, to construct a separate blender jar having a handle or like element and to have a holder into which the blender jar is fitted; typically, the bottom of the blender jar is open and is provided with suitable threads that are engaged by corresponding threads in the holder, which thus functions as a "nut". With such an arrangement, the fact that the jar is open at the bottom means that it can be thoroughly cleaned or scrubbed; likewise, the holder or nut on which the impeller or blade assembly is fixed is thereby so arranged that the blades are easily available for cleaning. In other words, unlike the earlier model or version, it is no longer necessary to reach down to the bottom of the blender jar in order to clean the blades.
It has also become a common mode of connecting the jar assembly to provide the holder with fluted sides involving spaced slots which are located such that a number of them will mate positively with corresponding elongated upstanding rubber cushions that extend radially inwardly from a crater or recess provided in the base or console of the blender device. By such an arrangement the two-part jar assembly is prevented from rotating in the blender base. However, while such a locking arrangement is satisfactory from the standpoint of providing positive locking of the complete jar assembly, a problem has arisen in that it is necessary to positively prevent the jar itself from unscrewing off the hand-tightened threaded jar nut when the blender is in operation. In other words, if the consumer should fail to tighten the nut to the jar sufficiently, it could happen that the blades in acting against a heavy chunky mass in the blender jar, would cause the jar to unscrew from the nut and possibly spin off the nut, thereby exposing the bare blades to the consumer.
Because of the concern about possible danger to the consumer, it has been proposed by certain government bodies that a standard be imposed whereby the rotation of the blades on a blender shall not tend to loosen either the blades or the container.
Accordingly, the present invention is directed to overcoming the aforedescribed problem so as to satisfy any governmental standards on consumer safety in this respect.
It is therefore a primary object of the present invention to provide an extremely inexpensive locking system that will provide positive locking of a blender jar to the holder or nut which receives such jar so as to prevent the jar from unscrewing from the holder when the blender is in operation.
Another object is to insure that the simplified locking system will not interfere with normal joining together of the blender jar with its receiving holder or nut.
The above objects are fulfilled and implemented by a primary feature of the present invention according to which the blender jar is constructed to have a small flange member projecting radially outwardly near the bottom of the jar. The lower end of the flange member on the blender jar just clears the upper surface of a flange provided in the plastic holder or nut.
A hole is provided in the flange of the holder with adequate clearance such that a lengthy pin or rivet can freely move therein. Thus, when the jar and holder are assembled in the appropriate orientation, that is, are upright, the pin will drop down by its own weight such that there will be no significant protrusion above the holder flange. However, when the jar assembly is placed on its base or console, contact of the holder flange with the rim adjacent the recess in the base will cause the pin or rivet to be forced upwardly, thereby to prevent movement of the jar by reason of the pin's engagement with the projecting flange member at the bottom of the jar. Accordingly, the jar is prevented from unscrewing from the holder.
Because of the various degrees of tightening to which the blender jar would ordinarily be subjected in being placed in the assembled state, sufficient leeway is allowed between the location of the pin on the holder and the outwardly projecting flange on the jar such that it will be insured that in all cases the desired prevention of movement will be accomplished. Moreover, because of the leeway permitted, any partial loosening of the holder means that a slight leakage will occur so as to alert the consumer that there is a loose assembly. In other words, since the pin or rivet will not ordinarily interfere with the flange until there has been some loosening, a desirable warning is effectuated.
Other and further objects, advantages and features of the present invention will be understood by reference to the following specification in conjunction with the annexed drawing, wherein like parts have been given like numbers.